Dishwashing method



March 29, 1960 J. B. TUTHILL DISHWASHING METHOD 2 Sheets-Sheet l FiledJuly 26, 1955 ATTO/e Eg March 29, 1960 J. B. TUTHILL msx-WASHING METHOD2 Sheets-Sheet 2 Filed July 2e, 1955 3: mm. om. md. ou. u: b: no. no. mmom nw om, E. mo ou w.6 o @SEE @.mlmozoomm z m2 INVENTOR.

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'assenza D isHwAsnrNG METHoD Violin B. TuthilhKansas City, Mo. f IApplication Jury 2,6,.i95s, serial No. 524,364

l l 5, claims. (ci. 134-25) nited States Pater pipe 42 provided withashut-otf valve 44. Alternately, i

ffice valve 24 withinthe body 2t) has an overflow pipe 26k operablycoupledrwith a solenoid V28, the pipe 26 being surrounded by a filteringymedium such as a removableV screen 30 within the valve body 20.

A water recirculation system is employed and includes i a pump 32-drivenby an kelectric motor 34 and having its inlet end vconnected with thebody 2t) above the valve 24 by a line 36,`the outlet end of the pump 32communicating-l with lthe manifold 1-6 through a line 38. Waterfrorn asupply line 40 may be introduced into the vat 10 above theoverow lineofthe latter-through a the water supply may be coupled with' the line 3,6through the medium of a Ypipe'lit having ashut-,oft' valve 48 inter-rposed therein;

A sterilizer container '54B and a container 52 for a` detergent, areconnected directly with the vat lil' above the water` level in thelatter for owiof materials by gravity thereinto through pipes 54 and' 56respectively, having lt is the most important object of theinstantfinvention to provide an improved dishwashing methody .that in'-Acorporates water-savingfeatures by utilizing theknal rinse of each cycleof operation as the liquid medium for the washing step of the nextsucceeding cycle.

Another important obect of the present invention is the provision of arecirculation method forV washing dishes includingautomaticallycleaning, during each cycle, the safety screen employed to` filter thecirculating liquidsand prevent clogging of the various parts of themachine. i

A further important objecty of this invention is to provide in adishwashing method, gravity ow introduction of a sterilizerand adetergent wherein the latter may either be in a powdered or liquid form.

A still further object of .this invention is to provide.

for atleast momentary discontinuance Vvof the recirculating systemduring'each cycle to: prevent theI possibility of air locking.

In the drawings:y

Figure 1 is a `chart showing schematically onetime schedule thatvmay beutilized in the method of washing Fig. 5. is. a side elevational Viewlof the` dishwashing c machine with. one. wall of the shell thereoflremoved and parts being brokenv away and in section .toY reveal Fig. 6.is. an enlarged; fragmentary, verticalpcrosssectionaljview Ithrough theoutlet conduit ofthe dish-l wasningvat; and Y Fig. 7 is a-.fragrnentary,cross-sectional view taken on line VIIe-VII of Fig. 6; v

Asshown in Figs. 2 and: 5'of',the drawings, there is provided.l a vatbroadly, designated by the numeral lll' thereof terminatingin a valvebody 20 that discharges to` waste by means of a drain pipe 22. Anormally closed..

1 7.0; and, therefore', thediscs thereon, rotate one cycle Operation ofmotor 34' and, therre- ,solenoid valves interposed' therein, thesolenoids where-V ofvrare designated by the numerals 5S and 60respectively. Y

ln the event a powdered detergent is employed,A water f-maybefintrodfucedintothe container 52 from the line 4t) by wayof a pipeA6I?. having asolenoid valve whose solenoidV is designated by thenumeral of. valve in the line lil between the line 42. and pipe 62, hasaV solenoid designated by the numeral 66.

"A1 timer shown*schematically'v in Fig. '2 includes a v" timer motor 68operablyy coupled with a cam shaft 7i) j upon which is mounted aplurality of cam discs, discs 72- and` 74I being associated withv thesolenoid 28, discs 76 and 7% being adapted' .tof control.. the solenoid66, disc 80 having an operablel connection with solenoidy 58,

disc 82- correspondingv to the solenoids 61k` and 64, vand disc 84controlling the motors .34 and 65.

Normally open` switches 72a, 7602,74@ title, 82a,

on shaft 70 forclosing upon register with thevarious indentationsprovided at the peripheries of the said discs.

:The disposition and lengths of such indentations inthe ydiscs may bestybe understood by viewingthe .chart eacha seconds. fore, pump 32,recirculates the liquid in the system from vat` 10, through drain i8,valve body 2i?,A line 36, pump 32, lineSS, and manifold :16, to washaway loose foreign?` `material, on the dishes. within tray i4, for aperiod of approximately six seconds. Thereupon, cam discySZl closesswitch` 82a, to inv turn energize solenoid 6G fonia Vperiod ofapproximately three seconds, as indicated lby shadedvarea 92, to admitdetergent from the 'container j 52, through pipe 56 and into the. vatitl.'

The detergent-admixes with the circulating liquidpresenting awater-.detergent admixture' which is sprayed over the. dishes inthe tray14.k After the machine has oper-YA ated lfor approximately 55 seconds,disc 74 closes switch 1 74a to energizesolenoid Z8 for approximately 13seconds as indicated by shaded area 94 in Fig. 1,1, during which timethe waterfdetergent admixture drains past valve 2d intofpipe 22.Although the pump 32 is still operating, itA

isseen that, while the liquid. is' beingdrained from the-V vat it?,.there will be no ilow'inl the line 35, and,1there fore, all filteredmaterial collected kon the inner surface A solenoid rsa. and 84a. are-disposedfadjacent the corresponding discs in line 40 is opened byvirtue of the operation' of disc 78, closing switch 78a and energizingsolenoid 66, thereby admitting fresh water into the vat either by way ofpipe 42 or pipe 46, depending upon which of the valves 44-48 is open. Y

After the machine is completely flushed clean of Waterdetergentadmixture, valve 24 re-closes and solenoid 66 remains energized for anadditional 20 seconds, as indicated by shaded area 96 in Fig. 1.However, while water is being admitted into the vat 10, disc 80 willhave moved to a position closing switch 80a, thereby energizing solenoid58 and causing a sterilizer to ow into vat 10 by gravity through pipe54. As indicated by shaded area 98 in Fig. 1, solenoid 58 remainsenergized for approximately three seconds.

The water-sterilizer admixture is recirculated over the Adishes in tray14 until the machine is operated for a total of 120 seconds, whereupondisc 72 closes switch 72a, thereby energizing solenoid 23 and againopening the valve 24 for a period of thirteen seconds as indicated byshaded area 100 in Fig. l. As soon as valve 24 recloses, the water valvein line 40 is again re-opened by energization of solenoid 66 because ofthe fact that disc 76 has opened switch 76a.

The water valve remains open for a period of twenty seconds, as shown byshaded area 102 in chart 90. The water thus admitted into the vat 10 isrecirculated until the completion of the cycle when switch 84a reopensand such water is utilized in the next cycle of operation for iinshingforeign matter from the dishes and for admixture with detergentemanating from container 52 when the solenoid 60 is energized because ofthe closing of switch 82a.

In the event it is desired to direct water into the detergent container52 upon closing of switch 82a, a manual switch 104 in series with thesolenoid 64, is closed, it being noted that switches 72a and 104 arelikewise coupled in series.

Oftentimes, by virtue of the aforedescribed cycle, the recirculationsystem becomes air-logged and, therefore, it becomes desirable tomomentarily deenergize the motor 34. This is accomplished by utilizing anormally closed switch idd which opens and remains open for threeseconds during the energization of solenoid 58 through closing of switch80a.

When switch 113 is in the position shown in Fig. 2, closing of manualswitch 87 energizes timer motor 68. It also energizes coil 107 of relay109 to close switch 111 of the latter. This energizes motor 34 throughswitch 111. As soon as disc 84 rotates to close switch 84a, motor 63 andcoil 107 remain energized even after opening of switch 87 until switch84a re-opens.

However, when switch 113 is placed in series with switch 106 (whileswitch 80a is open) coil 107 is energized to energize motor 34. throughswitch 111. When switch 87 is closed, motor 68 operates to cause closingof switch f Sita to permitV opening of switch 87. As soon as switch 80acloses, switch 106 opens, thereby deenergizing motor 34 for threeseconds.

Many governmental codes do not permit the rinsing away of thesterilizing solution from the dishes as provided in the above cycle.Accordingly, in Fig. 3 of the drawings, there is shown a chart 10Scontemplating a two and one-half minute cycle, wherein the opening ofvalve 24, as indicated by the shaded area 100, and the re-introductionof water as shown by shaded area 102, are eliminated. lt is seen thatunder such circumstances the sterilizerwater admixture is retained atthe end of each cycle and utilized with the detergent in the nextsucceeding cycle.

In comparing charts 9i) and 108, it is seen that in the latter, theperiod of time for cleansing the dishes with the detergent water, isincreased by approximately fifteen seconds, and that the dishes areactually sterilized for 4 eighteen additional seconds notwithstandingthe fact that the cycle of chart 108 is thirty seconds shorter than thecycle of chart 90.

Another embodiment is depicted by chart 110 in Fig. 4 that employs thesame time cycle as shown in chart so far as rinsing the dishes withdetergent water is concerned and also in sterilizing the dishes.However, as contemplated by chart 108, the sterilizer water is hereagain utilized in the next cycle of operation for receiving thedetergent.

Having thus described the invention what is claimed as new and desiredto be secured by Letters Patent is:

1. A method of cleaning and sterilizing soiled dishes which comprisesinterposing said dishes to be cleaned and sterilized within the normallyclosed circuit of a waterrecirculation system; gravitationally directinga detergent into said system for admixture and circulation with thewater; opening said circuit after a predetermined period of time todrain the water-detergent admixture therefrom; introducing apredetermined amount of rinse water into said system after draining fora predetermined period of time while the system continues to operate andwhile the circuit is open whereby to remove the admixture from thedishes and ush the same from the system; reclosing the circuit after apredetermined period of time; gravital tionally directing apredetermined quantity of sterilizer into said system while continuingto introduce rinse water; discontinuing introduction of rinse water; anddiscontinuing the recirculation of the water-sterilizer admixture aftera predetermined period of time following completion of the rinse waterintroduction.

2. A method of cleaning and sterilizing soiled dishes which comprisesinterposing said `dishes to be cleaned and sterilized within thenormally closed circuit of a continuously operating, water-recirculationsystem; gravitationally directing a detergent into said system foradmixture and circulation with the water; opening said circuit after apredetermined period of time to drain the water-detergent admixturetherefrom; introducing a pre determined amount of rinse water into saidsystem after draining for a predetermined period of time while thesystem continues to operate and while the circuit is open whereby toremove the admixture from the dishes and llush the same from the system;reclosing the circuit after a predetermined period of time;gravitationally directing a predetermined quantity of a sterilizer intosaid system while continuing to introduce rinse water; discontinuingintroduction of rinse water; discontinuing the recirculation of thewater-sterilizer admixture after a predetermined period of timefollowing completion of rinse water introduction while the circuit isclosed; and retaining said rinse water-sterilizer admxture Within saidclosed system whereby the rinse water-sterilizer admixture retained inthe system is used in the water-detergent admixture of the nextsucceeding cycle of operation.

3. A method of cleaning and sterilizing soiled dishes which comprisesinterposing said dishes to be cleaned and sterilized within the normallyclosed circuit of a water-recirculation system; gravitationallydirecting a detergent into said system for admixture and circulationwith the water; opening said circuit after a predetermined period oftime to drain the water-detergent admixture therefrom; introducing apredetermined amount of rinse water into said system after draining fora predetermined period of time while the system continues to operate andwhile the circuit is open whereby to remove the admixture from thedishes and flush the same from the system; reclosing the circuit after apredetermined period of time; gravitationally 'directing a predeterminedquantity of a sterilizer into said system while continuing to introducerinse water; discontinuing recirculation while introducing thesterilizer; resuming recirculation to rinse the dishes withwater-sterilizer admixture; discontinuing introduction of rinse water;discontinuing the recirculation of the Water-sterilizer admixture aftera predetermined period of time following completion of rinse Waterintroduction while the circuit is closed; and retaining said rinsewater-sterilizer admixture within said closed system whereby the rinseWater-sterilizer admixture retained in the system is used in thewater-detergent admixture of the next succeeding cycle of operation.

4. A method of cleaning and sterilizing soiled dishes which comprisesinterposing said dishes to be cleaned and sterilized within the normallyclosed circuit of a continuously operating, water-recirculation system;gravitationally ydirecting a detergent into said system for admixtureand circulation with the water; opening said circuit after apredetermined period of time to drain the water-detergent admixturetherefrom; introducing a predetermined amount of rinse water into saidsystem after draining for a predetermined period of time while thesystem continues to operate and while the circuit is open whereby toremove the admixture from the dishes and ush the same from the system;reclosing the circuit after a predetermined period of time;gravitationally directing a predetermined quantity of a sterilizer intosaid system while continuing to introduce rinse water; discontinuingintroduction of rinse water; opening said circuit after a predeterminedperiod of time following completion of rinse water introduction anduntil the water-sterilizer admixture is drained therefrom; reclosing thecircuit; introducing a predetermined amount of water into the system forsubjecting the dishes to a second rinse; discontinung the recirculationof the second rinse water while the circuit is closed; and retainingsaid second rinse water within said closed system whereby said secondrinse water retained in the system is used in the water-detergentadmixture of the next succeeding cycle of operation.

5. A method of cleaning and sterilizing soiled dishes which comprisesinterposing said dishes to be cleaned and sterilized within the normallyclosed circuit of a water-recirculation system; gravitationallydirecting a de- 6 tergent into said system for admixture and circulationwith the water; opening said circuit after a predetermined period oftime to drain the water-detergent admixture therefrom; introducing apredetermined amount of rinse water into said system after draining fora predetermined period of time while the system continues to operate andwhile the circuit is open whereby to remove the admixture from thedishes and flush the same from the system; reclosing the circuit after apredetermined period of time; gravitationally directing a predeterminedquantity of a sterilizer into said system While continuing to introducerinse water; discontinuing recirculation while introducing thesterilizer; resuming recirculation to rinse the dishes withwater-sterilizer admixture; discon# tinuing introduction of rinse water;opening said circuit after a predetermined period of time followingcompley.

tion of rinse water introduction and until the watersterilizer admixtureis drained therefrom; reclosing the circuit; introducing a predeterminedamount of water into the system for subjecting the dishes to a secondrinse; discontinuing the recirculation of the second rinse Water whilethe circuit is closed; and retaining said second rinse water within saidclosed system whereby said second rinse water retained in the system isused in the Water-detergent admixture of the next succeeding cycle ofoperation.

References Cited in the' tile of this patent UNITED STATES PATENTS1,737,794 Henderson Dec.v3, 1929 2,025,571 Clark Dec. 24, 1935 2,275,189Y Wieghart ...7.... Mar. 3, 1942 2,385,264 Ferris Sept. 18, 19452,390,757 Voris Dec. 11, 1945 2,642,369V Hunter June 16, 1953 2,718,481Tuthill Sept. 20, 1955

1. A METHOD OF CLEANING AND STERILIZING SOILED DISHES WHICH COMPRISESINTERPOSING SAID DISHES TO BE CLEANED AND STERILIZED WITHIN THE NORMALLYCLOSED CIRCUIT OF A WATERRECIRCULATION SYSTEM? GRAVITATIONALLY DIRECTINGA DETERGENT INTO SAID SYSTEM FOR ADMIXTURE AND CIRCULATION WITH THEWATER? OPENING SAID CIRCUIT AFTER A PREDETERMINED PERIOD OF TIME TODRAIN THE WATER-DETERGENT ADMIXTURE THEREFROM? INTRODCING APREDETERMINED AMOUNT OF RINSE WATER INTO SAID SYSTEM AFTER DRAINING FORA PREDETERMINED PERIOD OF TIME WHILE THE SYSTEM CONTINUES TO OPERATE ANDWHILE THE CIRCUIT IS OPEN WHEREBY TO REMOVE THE ADMIXTURE FROM THEDISHES AND FLUSH THE SAME FROM THE SYSTEM? RECLOSING THE CIRCUIT AFTER APREDETERMINED PERIOD OF TIME? GRAVITATIONALLY DIRECTING A PREDETERMINEDQUANTITY OF STERILIZER INTO SAID SYSTEM WHILE CONTINUING TO INTRODUCERINSE WATER? DISCONTINUING INTRODUCTION TO RINSE WATER? ANDDISCONTINUING THE RECIRCULATION OF THE WATER-STERILIZER ADMIXTURE AFTERA PREDETERMINED PERIOD OF TIME FOLLOWING COMPLETION OF THE RINSE WATERINTRODUCTION.